5.02.2007

Millions of women in the United States ingest excess estrogen every day in the form of birth control pills. Within 24 hours, the effluent from those 12 million doses ends up in our sewage systems. And then?

The April 17 Scientific American reported results of a study warning that “many streams, rivers and lakes already bear warning signs that the fish caught within them may also be carrying enough chemicals that mimic the female hormone estrogen to cause breast cancer cells to grow.”

“Fish are really a sentinel, just like canaries in the coal mine 100 years ago,” says Conrad Volz, co-director of exposure assessment at the University of Pittsburgh Cancer Institute's Center for Environmental Ecology. “We need to pay attention to chemicals that are estrogenic in nature, because they find their way back into the water we all use.”

According to the Freshwater Institute’s Fisheries and Oceans section, “The potent synthetic estrogens excreted by women taking hormone replacement therapy or birth control pills are not completely broken down in the sewage treatment process and are discharged into waterways.”

While cautioning that the exact process of hormonal confusion is not yet clear, the Scientific American article continued, “But the [estrogenic] effects on the fish themselves were clear: the gender of nine of the fish [tested] could not be determined.”

“Increased estrogenic active substances in the water are changing males so that they are indistinguishable from females,” Volz found. “There are eggs in male gonads as well as males are secreting a yolk sac protein. Males aren't supposed to be making egg stuff.”